/Engine/Plugins/Interchange/Runtime/Source/Nodes/Public/InterchangeShaderGraphNode.h
Returns true if the attribute key is associated with an input (starts with "Inputs:").
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Interchange | Node | Material") static bool IsAnInput ( const [FString](API\Runtime\Core\Containers\FString) & AttributeKey )